In line air filtration and purification apparatus

ABSTRACT

A method and apparatus for an inline air purification system is described herein. An example apparatus includes a housing, a high-velocity air flow guide, a filter assembly, and a fan. The high-velocity air flow guide includes a first portion and a second portion. The first portion is configured to form a passage within the housing, and the second portion is configured to divert and accelerate air flow of the ambient air from the passage to a chamber of the housing. The filter assembly includes one or more filtering elements configured to receive the ambient air from the chamber. The fan is configured to draw the ambient air from the chamber through the filter assembly and to generate processed air from the ambient air. The housing is located in an HVAC duct, and occupies only part of the cross-sectional area of the duct. The remaining area of the duct accommodates bypass air flow to a primary fan in the HVAC system.

PRIORITY OF INVENTION

This application is a continuation of and claims priority to applicationSer. No. 15/633,370, which issued as U.S. Pat. No. 10,584,885 on Mar.10, 2020 which is a Continuation of and claims priority to applicationSer. No. 13/836,401, which issued as U.S. Pat. No. 9,689,580 on Jun. 27,2017, and is further a Continuation in Part and claims priority ofapplication Ser. No. 11/098,202, filed Apr. 4, 2005, which issued asU.S. Pat. No. 8,123,836 on Feb. 28, 2012.

FIELD OF THE INVENTION

The present disclosure relates generally to inline air filtration andpurification, and more particularly, to a method and apparatus forprocessing air moving in a duct of an HVAC system.

Although certain example methods and apparatuses have been describedherein, the scope of coverage of this patent is not limited thereto. Onthe contrary, this patent covers all embodiments and modificationsfalling within the scope of the appended claims either literally orunder the doctrine of equivalents.

Background of the Invention and Prior Art

This application is a continuation in part of application Ser. No.13/405,991 which is a continuation of application Ser. No. 11/098,202,now U.S. Pat. No. 8,123,836.

Concern over air quality has triggered some developments in the area ofindoor air quality improvement and/or control. Such developments havetypically resulted in the production of various types of air processingsystems including air filtration systems. Air filtration systems aresometimes differentiated according to air filtering capabilities and mayinclude air filtration devices designed to be integrated within aheating, ventilation, and air conditioning (HVAC) system, or local orunitary air filtration devices. Air filtration devices configured to beintegrated with HVAC systems (i.e., integrated air filtration devices)are typically capable of filtering large amounts of ambient air such as,for example, an amount of ambient air that fills a warehouse, an officebuilding, an apartment building, a house, an entertainment hall, etc. Incontrast, local or unitary air filtration devices are typicallyconfigured to filter an amount of ambient air associated with a localarea such as, for example, an office, a bedroom, a bathroom, etc. Theequipment described here is for use in an HVAC system.

Air filters in existing air filtration devices maybe inefficiently usedbecause of the angle at which ambient air enters and is drawn throughthe air filters. In particular, in some cases only a relatively smallarea or space of an air filter is used effectively to trap particleswhile the rest of the air filter remains unused. As a result, themaintenance cost of air filtration devices may increase because airfilters may be prematurely replaced and/or air flow throughput maydecrease because the air filtration devices may be frequently turned offfor cleaning of the air filters.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an example air processing system configured in anexisting system.

FIG. 2 depicts a front view of a receiving surface of a filter assemblyof the example air processing system of FIG. 1.

FIG. 3 depicts an example of a high-velocity air processing systemconfigured in accordance with the teachings disclosed herein.

FIG. 4 depicts a front view of a receiving surface of a filter assemblyof the example high-velocity air processing system of FIG. 3.

FIG. 5 is a block diagram of an exemplary processor system that may beused to implement the method and apparatus described herein.

FIG. 6 depicts an example of a high-velocity air processing systemincorporated into an HVAC duct in accordance with the teachingsdisclosed herein.

SUMMARY OF THE INVENTION

In general, a method and apparatus for processing air flowing in an HVACsystem are disclosed herein. An example apparatus for processing airincludes a duct, a housing, a filter assembly, a fan, and ahigh-velocity air flow guide. The filter assembly includes one or morefiltering elements configured to generate filtered air based on ambientair in a chamber of the housing. The fan is configured to draw part ofthe air flowing through the duct into a chamber and through the filterassembly to generate processed air. The high-velocity air flow guideincludes an upstanding portion and a support portion having a firstportion and a second portion. In particular, the first portion isconfigured to form a passage within the housing, and the second portionis configured to divert the ambient air from the passage to the chamber.The second portion is configured to accelerate the air flow from a firstspeed to a second speed into the chamber prior to the fan drawing theambient air from the chamber through the filter assembly. Thus, a crosssection view of the air flow from the chamber is substantially the sameas the surface area of the receiving portion of the filter assembly. Bydistributing a volume of ambient air over a greater portion of the frontof the filter assembly, the air filters of the filter assembly are usedin a relatively efficient manner, and the maintenance cost of the filterassembly may be reduced.

Only a part of the air flow in the duct is processed. The remainder ofthe air flow bypasses the housing, guide, chamber, filter, and fan. Thisbypass air flows directly to the primary fan or blower in the HVACsystem. The processed air rejoins and mixes with the by passed air.Because the air mixes, substantially all of the air in the HVAC systemis ultimately processed through the filtration system as the air in thesystem recirculates. Because only a part of the airflow is processed,the primary fan is not starved of air. The two flows can be balanced tooptimize filtration while insuring that problems that might result fromstarving the primary fan or blower are avoided. For example, acombustion or cooling unit in the HVAC will be supplied with adequateflow to avoid over heating or a reduction in cooling.

Referring to FIG. 1, an air processing system 100 configured in a knownmanner typically includes a housing 110, an air flow guide 120, a filterassembly 130, and a fan 140. In general, the air processing system 100receives ambient air from an intake vent 150 of the housing 110 into apassage 160. The air flow guide 120 is configured to divert or guide theambient air through the passage 160 and into a chamber 170 of thehousing 110. The filter assembly 130 includes one or more air filters122, 124, and 126, to filter the ambient air from the chamber 170. Thefan 140 draws the ambient air from the chamber 170 into the filterassembly 130 via a receiving surface 180 of the filter assembly 130.Typically, the fan 140 immediately draws the ambient air from thepassage 160 into the filter assembly 130 in a direction generallyindicated by arrows 190. The air flow indicated by the arrows 190 doesnot permit the chamber 170 fill with ambient air prior to the fan 140drawing the ambient air through the filter assembly 130.

Turning to FIG. 2 as an example, the ambient air is substantiallyfiltered through a lower-center portion 210 of the receiving surface 180of the filter assembly 130. The upper, left, and right portions,generally shown as 220, 230, and 240, respectively, of the receivingsurface 180 are substantially unused. Thus, each of the one or morefilters of the filter assembly 130 traps contaminants and, thus, becomesclogged in the lower-center portion 210.

Turning now to FIG. 3, a high velocity air processing system 300configured in accordance with the teachings of the present disclosure isillustrated. The high-velocity air processing system 300 includes ahousing 310, a high-velocity air flow guide 320, a filter assembly 330,and a fan 340. In general, the high-velocity air processing system 300receives ambient air from an intake vent 350 of the housing 310 via apassage 360. The intake vent 350 may be configured to operate incombination with the high-velocity air flow guide 320 as described indetail below by enabling ambient air to flow into a chamber 370 of thehousing 310 in a direction generally indicated by arrows 990. The intakevent 350 may include a grate, a screen, and/or a large particle filter(none of which are shown). In one implementation, a layeredconfiguration for the intake vent 350 may include the grate as theoutermost layer followed by the screen, and the large particular filteras the innermost layer. The grate may be impact resistant to preventdamage to the screen, the large particle filter, and the portions of thehigh-velocity air processing system 300 located within the housing 310.The screen may be configured to prevent relatively large objects (e.g.,paper, coins, food, etc.) from entering into the housing 310. The largeparticle filter may be configured to prevent relatively large particles(e.g., dust, hair, lint, liquid, etc.) from entering the housing 310.

Although the housing 310 is shown as having a relatively cubicalstructure, any other geometry or structure may be used to implement thehousing 310 including, for example, a pyramidal structure, a cylindricalstructure, a trapezoidal structure, etc. In the illustrated example,however, the housing 310 is cubical in shape and includes a bottom panel311A, a plurality of upstanding side panels 311B, and a top panel 311C.The intake vent 350 is approximately centrally located in the bottompanel 311A, thereby enabling air to be drawn into the chamber 370through the bottom of the housing 310. The housing 310 may include atleast one vertical riser (not shown) upon which the housing 310 sits,such that the intake vent 350 is elevated above a support structure ofthe housing (e.g. a floor), to allow air to flow into the chamber 370through the intake vent 350.

The high-velocity air flow guide 320 includes an upstanding portion 320Aextending upward from the bottom panel 311A, and a support portion 320Bextending over and generally parallel to the face of the vent 350. Thesupport portion 320B is adapted to support the filter assembly 330. Asshown, the filter assembly 330 is centrally located in the housing 310and rests upon the support portion 320B of the high-velocity air flowguide 320. While the filter assembly 330 is shown as extending less thanthe distance between the support portion 320B and the top panel 311C,the filter assembly 330 and each individual filter within the assembly330 may extend any amount between the support portion 320B and the toppanel 311C.

Also located with the housing 310 is the fan 340. The fan 340 is locatedto a side of the filter assembly 330 opposite the chamber 370. The fan340 includes an output vent 342 located in the top panel 311C. Theoutput vent 342 allows the fan 340 to draw air from the chamber 370through the filter assembly 330 and exhaust out the vent 342.

The housing 310 may also include an access panel and/or a control panel(neither of which are shown). The access panel may be configured toenable access to the filter assembly 330 and/or the fan 340 within thehousing 310 for maintenance, inspection, and/or any other purpose. Thecontrol panel may be mechanically and/or electrically coupled to thehousing 310 and configured to provide data input and output capabilitiesfor controlling and/or monitoring any aspect of the high-velocity airprocessing system 300. For example, the control panel may be used tocontrol operational states of the high-velocity air processing system300. In addition, the control panel may be used to access statusinformation associated with operations and/or status of thehigh-velocity air processing system 300.

The support portion 320B of the high-velocity air flow guide 320 (e.g.,an air flow guide) includes a first portion 322 and a second portion324. The high-velocity air flow guide 320 may be implemented usingplastic, metal, and/or other suitable material. The first portion 322 isconfigured to receive ambient air from the intake vent 350 (i.e., anintake structure) and form the passage 360 in conjunction with theintake vent 350. The second portion 324 is configured to accelerate theambient air from the passage 360 into a chamber 370 of the housing 310to generate a high-velocity air flow in a direction generally indicatedby the arrows 990. In particular, the second portion 324 diverts orguides the ambient air into the chamber 370 so that the ambient air isgenerally evenly distributed relative to a receiving surface 380 of thefilter assembly 330 as the fan 340 draws the ambient air from thechamber 370 through the filter assembly 330. The second portion 324 maybe, for example, a radial portion or curved lip to accelerate theambient air into the chamber 370 in the manner shown and described. Forexample, the air traveling through the passage 360 may accelerate overthe radial second portion 324 so that the speed of the air after theradial second portion 324 is greater than the speed of the air in thepassage 360.

Referring now to FIG. 4, in this example, the second portion 324 divertsor guides the ambient from the passage 360 into the chamber 370 so thatmore area of the receiving surface 380 of the filter assembly 330 isused. By distributing the ambient air more evenly throughout thereceiving surface 380, the second portion 324 increases air flowthroughput. In contrast to the receiving surface 180 shown in FIGS. 1and 2 for example, the second portion 324 diverts ambient air from thepassage 360 and accelerates air flow of the ambient air into the chamber370 prior to the fan 340 drawing the ambient air through the filterassembly 330. Thus, the time between filter replacements or cleaningsmay be extended. For example, the filter assembly 330 may be rated foroperation based on an amount of time or a volume of air that isprocessed. In particular, the filter assembly 330 may be rated tooperate for a predetermined amount of time (at a constant flow) beforeneeding to be replaced or cleaned. Alternatively, the filter assembly330 may be rated to operate for a predetermined total volume of airbefore needing to be replaced or cleaned. By increasing the life of thefilter assembly 330, maintenance costs may be reduced.

Although the high-velocity air flow guide 320 is depicted in FIG. 3 as asingle, integrated structure, the upstanding portion 320A and thesupport portion 320B including the first portion 322 and the secondportion 324 may be separate structures operatively coupled to eachother. For example, the second portion 324 may be a separate structure,adjustably coupled to the first portion 322 so that the second portion324 may be adjusted to increase/decrease the second air flow speed. Forinstance, the second portion 324 may be flexibly or pivotally attachedto the first portion 322.

The filter assembly 330 may include a plurality of air filter elements,generally shown as a first filter 332, a second filter 334, and a thirdfilter 336 to process the ambient air from the chamber 370. For example,the first filter 332 may be a pre-filter, the second filter 334 may be aHigh Efficiency Particulate Accumulator (HEPA) filter, and the thirdfilter 336 may be a charcoal filter. In particular, the first filter 332may be an electrostatic filter or a pleated filter having antimicrobialproperties. The first filter 332 may be used to pre-filter the ambientair that is drawn into the housing 310 via the intake vent 350 to removerelatively large pollutants or particles (e.g., dust, lint, etc.) fromthe ambient air. The HEPA filter used to implement the second filter 334may be used to capture many bacteria, viruses, allergens (e.g., pollens,spores, smoke, etc.), and other relatively small organisms or particlesthat may be found in ambient air. The charcoal filter used to implementthe third filter 336 may be used to remove volatile organic compounds(VOC) (e.g., certain chemicals, gases, etc.) and odors from the ambientair.

Although the filter assembly 330 is depicted in FIG. 3 to include threefilters, the filter assembly 330 may include more or fewer filters.Further, the illustrated filter assembly 330 is positioned so that thereceiving surface 380 of the filter assembly 330 is substantiallyperpendicular relative to the intake vent 350. That is, the receivingsurface 380 is parallel to a plane that is substantially perpendicularto the intake vent 350. In this manner, the ambient air is drawn intothe housing 310 by the fan 340 via the intake vent 350 in a directiongenerally indicated by arrows 990. Alternatively, the filter assembly330 may be skewed at an angle relative to the intake vent 350. Forexample, the receiving surface 380 may be parallel to a plane thatintersects the intake vent 350 at an angle other than perpendicular.Further, one filter of the filter assembly 320 may be disposed in afirst position relative to the intake vent 350 and another filter of thefilter assembly 330 may disposed in a second position relative to theintake vent 350.

For example, the first filter 332 may be skewed at an angle relative tothe intake vent 350, whereas the second filter 334 may be substantiallyperpendicular relative to the intake vent 350.

The fan 340 may be a squirrel cage fan, or any other type of fanconfigured to draw ambient air from the intake vent 350 into the housing310 through the filter assembly 330 and push or exhaust processed airout of the housing 310 through the vent 342. The fan 340 may be avariable speed fan communicatively coupled to and controlled by aninformation processing system 390 via a link 392. For example, the speedof the fan 340 may be controlled based on information received by theinformation processing system 390.

The information processing system 390 may be implemented using anyprocessing system, including, by way of example, a computer, anapplication specific integrated circuit (ASIC), a processor system orother suitable device. In this example, the information processingsystem 390 is a processor system 2000 illustrated in FIG. 5 andconfigured to control and/or monitor operations of the high-velocity airprocessing system 300. The information processing system 390 may becommunicatively coupled to the control panel (not shown) and configuredto receive commands entered via the control panel by a person. Inaddition, the information processing system 390 may be configured todisplay information via the control panel, or other suitable display.

The method and apparatus disclosed herein may be integrated withindevices such as, for example, a kiosk, an information booth, anautomated teller machine, a public telephone, an advertisementapparatus, a computer terminal, etc. to process ambient air.

FIG. 5 is a block diagram of an example processor system 2000 adapted tobe implemented as the information processing system 390. The processorsystem 2000 may be, for example, a desktop computer, a personalcomputer, a dedicated computer, a laptop computer, a notebook computer,a personal digital assistant (PDA), a server, an Internet appliance orany other type of computing device.

In this example, the processor system 2000 illustrated in FIG. 5includes a chipset 2010, which includes a memory controller 2012 and aninput/output (I/O) controller 2014. As is well known, a chipsettypically provides memory and I/O management functions, as well as aplurality of general purpose and/or special purpose registers, timers,etc. that are accessible or used by a processor 2020. The processor 2020is implemented using one or more processors. The processor 2020 includesa cache 2022, which may be implemented using a first-level unified cache(L1), a second-level unified cache (L2), a third-level unified cache(L3), and/or any other suitable structures to store data.

As is conventional, the memory controller 2012 performs functions thatenable the processor 2020 to access and communicate with a main memory2030 including a volatile memory 2032 and a non-volatile memory 2034 viaa bus 2040. The volatile memory 2032 may be implemented by SynchronousDynamic Random Access Memory (SDRAM), Dynamic Random Access Memory(DRAM), RAMBUS Dynamic Random Access Memory (RDRAM), and/or any othertype of random access memory device. The non-volatile memory 2034 may beimplemented using flash memory, Read Only Memory (ROM), ElectricallyErasable Programmable Read Only Memory (EEPROM), and/or any otherdesired type of memory device.

The processor system 2000 also includes an interface circuit 2050 thatis coupled to the bus 2040. The interface circuit 2050 may beimplemented using any type of well known interface standard such as anEthernet interface, a universal serial bus (USB), a third generationinput/output interface (3GIO) interface, and/or any other suitable typeof interface. Additionally, the interface 2050 may couple the processingsystem to the fan 240 via the link 392.

One or more input devices 2060 are connected to the interface circuit2050. The input device(s) 2060 permit a user to enter data and commandsinto the processor 2020. For example, the input device(s) 2060 may beimplemented by a keyboard, a mouse, a touch-sensitive display, a trackpad, a track ball, an isopoint, and/or a voice recognition system.

One or more output devices 2070 are also connected to the interfacecircuit 2050. For example, the output device(s) 2070 may be implementedby display devices (e.g., a light emitting display (LED), a liquidcrystal display (LCD), a cathode ray tube (CRT) display, a printerand/or speakers). The interface circuit 2050, thus, typically includes,among other things, a graphics driver card.

The processor system 2000 also includes one or more mass storage devices2080 to store software and/or data. Examples of such mass storagedevice(s) 2080 include floppy disks and drives, hard disk drives,compact disks and drives, and digital versatile disks (DVD) and drives.

The interface circuit 2050 also includes a communication device such asa modem or a network interface card to facilitate exchange of data withexternal computers via a network. The communication link between theprocessor system 2000 and the network may be any type of networkconnection such as an Ethernet connection, a digital subscriber line(DSL), a telephone line, a cellular telephone system, a coaxial cable,etc.

Access to the input device(s) 2060, the output device(s) 2070, the massstorage device(s) 2080 and/or the network is typically controlled by theI/O controller 2014 in a conventional manner. In particular, the I/Ocontroller 2014 performs functions that enable the processor 2020 tocommunicate with the input device(s) 2060, the output device(s) 2070,the mass storage device(s) 2080 and/or the network via the bus 2040 andthe interface circuit 2050.

While the components shown in FIG. 5 are depicted as separate blockswithin the processor system 2000, the functions performed by some ofthese blocks may be integrated within a single semiconductor circuit ormay be implemented using two or more separate integrated circuits. Forexample, although the memory controller 2012 and the I/O controller 2014are depicted as separate blocks within the chipset 2010, the memorycontroller 2012 and the I/O controller 2014 may be integrated within asingle semiconductor circuit.

In one example of operation, the processor system 2000 may control thespeed of the fan 340 to process air through the air processing system300. For instance, the processor system 2000 may start the fan 340,causing air to be drawn into the system 300. The system 300 receives theambient air from the intake vent 350 of the housing 310 wherein theambient air is diverted by the air flow guide 320 in the chamber 370through the passage 360. The air flow guide 320 accelerates the air flowfrom a first air flow speed to a greater second air flow speed as thesecond portion 324 of the support portion 320B diverts the air into thechamber 370. The second portion 324 diverts or guides the ambient airfrom the passage 360 into the chamber 370 so that more area of thereceiving surface 380 of the filter assembly 330 is used. For instance,a cross sectional view of the air flow from the chamber 370 onto thefilter assembly 330 is substantially the same as the area of thereceiving surface 380 of the filter assembly 330. From there, theambient air travels through the filter assembly 330, into the fan 340,and exhausts out the vent 342 as processed and filtered air.

FIG. 6 shows a high-velocity air processing system 600 incorporated intoa duct 680 of an HVAC system. The duct walls 681 enclose processingsystem 600. Air enters at the top of FIG. 6. A housing 610 has walls611A, 611B, and 611C. The housing supports a fan 640 and filters 632,634 and 636 to process air from chamber 670. As with FIG. 3, the filtersmay be of different types, and fewer or more filters may be used. Thehousing, as before, may be differently shaped depending, for example, onduct size or shape and the location of processing system 600 in duct680.

Housing wall 611B separates the airflow being processed from theremaining air, which flows through bypass 672, continuing to a primaryHVAC fan that is not shown. Duct wall 611B terminates at a point pastthe outlet of fan 640. Processed air is free at that point to mix withair passing through bypass 672.

A high-velocity air flow guide 620 may be formed with housing wall 611A.Guide 620 and wall 611A can also be separate structures. Guide 620includes a first portion 622 and a second portion 624. First portion622, cooperating with duct wall 611B, causes the incoming air flow toturn so that it can enter a chamber 670. Second portion 624 acceleratesthe air flow into chamber 670 so the airflow is distributedapproximately as shown by arrows 690. As in the case of FIG. 3, theairflow is delivered to the face of first filter 632 at approximately aright angle. Filter efficiency is enhanced as described in thediscussion of FIG. 3 and FIG. 4. Portions 622 and 624 can be separatestructures. For example, second portion 624 could be hinged so that itis adjustable.

Filters 632, 634, and 636 are shown as approximately parallel to thepath of incoming air. As with FIG. 3, the filters may be oriented atanother angle with respect to the airflow, or the filters may be atangles which differ from each other.

Fan 640 is supported by any convenient means. It draws air from filters632, 634 and 636, through a plenum 638 in housing 610. Fan 640 exhaustsair between plenum 638 and housing wall 611B. Once wall 611B ends,processed air mixes with the balance of the air traveling through bypass672. Mixing and recirculation of air in the HVAC system causes all theair in the system to be process by processing system 610.

The processor system of FIG. 5 may also be used with the system of FIG.6.

What is claimed is:
 1. An HVAC system for providing inline airpurification for an air stream comprising: a ductwork section having agiven air flow cross-sectional area for drawing an air stream in a firstgiven direction therethrough; a diverter for diverting a first portionof the air stream in at least a second given direction that issubstantially orthogonal to the first given direction, the secondportion of the air stream remaining flowing in the first givendirection; a filter assembly including at least one filtering elementand a fan for drawing the first portion of the air stream with a filterassembly fan through the at least one filtering element configured toreceive a first portion of the airstream from a chamber of a housinglocated with the HVAC ductwork section, the filtering elements beingsubstantially orthogonal to the second given direction; and a bypassduct for receiving the second portion of the air stream such that thesecond portion is not drawn by the filter assembly fan through thefiltering elements, whereby the bypass duct and the filter assembly fanminimizes the pressure drop occurring as a result of drawing the firstportion of the air stream through the filter element.
 2. An HVAC systemfor processing an air stream comprising: a ductwork section having agiven air flow cross-sectional area for drawing an air stream in a firstgiven direction therethrough; a high-velocity air flow guide disposedwithin the ductwork section for diverting a first portion of the airstream in at least a second given direction that is substantiallyorthogonal to the first given direction the second portion of the airstream remaining flowing in the first given direction, the high-velocityair flow guide comprising a first section, and a second, curved section;a filter assembly including at least one filtering element and a fan fordrawing the first portion of the air stream with a filter assembly fanthrough the at least one filtering element configured to receive thefirst portion of the airstream from a chamber of a housing located withthe HVAC ductwork section, the filtering elements being substantiallyorthogonal to the second given direction; and a bypass duct forreceiving the second portion of the air stream such that the secondportion is not drawn by the filter assembly fan through the filteringelements, whereby the bypass duct and the filter assembly fan minimizesthe pressure drop occurring as a result of drawing the first portion ofthe air stream through the filter element.